Gets the overlay bitmap of this L_OcrPage (if the page has one).
Handle to the OCR page.
Address to BITMAPHANDLE variable to be updated with the page overlay bitmap.
Size of the BITMAPHANDLE structure, use sizeof(BITMAPHANDLE).
|SUCCESS||The function was successful.|
|< 1||An error occurred. Refer to Return Codes.|
By default, the overlay image is the original image used to create the page. It is the same value obtained by calling L_OcrPage_GetBitmap with L_OcrPageBitmapType_Original option.
In some situation, the user might want to use a different bitmap as the overlay. For example, a smaller version is passed to the OCR engine to conserve memory while the original version will only be used on save purposes in a PDF with image/text option. You can call L_OcrPage_SetOverlayBitmap before saving the document (memory-based) or adding the page to the document (file-based) and the engine will use this new bitmap as the overlay value. If auto-preprocessing was performed on the page through L_OcrPage_AutoPreprocess, then the same values might need to be applied to the overlay as well. Use L_OcrPage_GetAutoPreprocessValues to get the accumulative values of any inversion, rotation or deskewing applied by the pre-processor.
To clear the temporarily overlay image, call L_OcrPage_SetOverlayBitmap with a NULL value.
To get the overlay image at any time, call L_OcrPage_GetOverlayBitmap. Note that this property will return the same image reference passed to the last L_OcrPage_SetOverlayBitmap call. It will not return the original image.
The overlay bitmap is not freed by this L_OcrPage.
Required DLLs and Libraries
For an example, refer to L_OcrPage_SetOverlayBitmap